Shock absorber



D. A. AVNER SHOCK ABSORBER Jan. 12, 1965 Filed May 28, 1963 gamma and *kann Httwnefws United States Patent C M 3,165,176 SHCK ABSER David Alan Avner, Coventry, England, assigner to Gil-1mg Limited, Birmingham, England, a British tCompany Filed May 28, 1963, Ser. No.. 283,755 Claims priority, application Great Britain .lune 30, 1962 1 Claim. (Cl. 13S-96) This invention relates to improvements in telescopic dampers of the single tube type in which a piston reciprocates in a cylinder lled with iluid and the piston incorporates a valve of the annular llexible plate or strip type controlling the ow of liuid through the piston in both directions.

According to our invention, in a damper of that kind the loading of the valve in the piston is adjustable by means of a nut in screw-threaded engagement with the piston-rod, and the nut carries means whereby, when the damper is` extended, the nut is keyed to an end closure of the cylinder or a part non-rotatably associated ywith the end closure so that the axial position of the nut member and hence the loading of the valve can be adjusted by rotation of the piston-rod relative to the damper body.

The spring-loading of the valve in lthe piston can thus be rapidly and easily adjusted after disconnecting the piston-rod or the cylinder from the part of a vehicle or the like to which it is attached, and it is not necessary to dismantle the damper.

One form of damper embodying our invention is illustrated by way of example in the accompanying drawing which is a longitudinal section of the damper.

The body of the damper illustrated is formed by a cylinder 1t) closed at its upper end which carries an extension 11 by which the cylinder is connected to a part of a vehicle. Working in the cylinder is a piston 12 secured to the upper end of a piston-rod llworking through a seal 14 and a guide 15 forming a closure for the lower end of the cylinder. The projecting portion of the piston-rod is protected by a boot 16 of bellows form attached at its ends to the closure 15 and the rod respectively, and the extremity of the rod carries an attachment eye 17.

A floating piston 1S provided with an O-ring or other seal 19 is located in the cylinder between the piston 12 and the upper end ot' the cylinder.

The flow of fluid through the piston 12 in both directions is controlled by a valve formed by an annular shim l or by a number of superimposed annular ilexible plates or shims 21 located between an annular seating Z2 on the underside of the piston and an oppositely directed annular seating 23 of smaller diameter on a nut 24 in screwthreaded engagement with the piston-rod immediately below the piston. A passage 25 Vextends throughL the piston above the valve or there may be a series of such passages.

The shims 21 can flex in either direction to allow liquid to pass through the piston in both directions at controlled pressures determined by the axial position of the seating on the nut relative to the seating on the piston.

lbl? Patented Jan. 12, 1965 ICC The nut is provided on its lower face, that is the face remote from the nut, with an axially projecting dog 26 which, when the damper is fully extended, is adapted to engage in any one of a' ring of holes 2'7 in a dished washer 28 located against the end closure 1S and heldagainst angular movement relative to the cylinder.

ring 23 or other insert located in an annular recess in the bore of the nut and engaging the screw-thread on thepiston-rod. v

T he nut may have'a small bleed orice 29 through it for the passage of fluid through it independently of the valve, and the rate of flow through this orilice may also be controlled by the adjustment of the nut which varies the spacing between -the nut and the adjacent end of the piston.

l claim: l

Al telescopic damper comprising a cylinder adapted to be lled with iluid, a piston working in the cylinder, a piston-rod attached to the piston and working through an end closure for the cylinder, a nut in screw-threaded engagement with the piston-rod adjacent to the piston, an annular valve seating on the piston directed towards theA nut, an oppositely directed concentric Valve seating on the nut, a valve member comprising at least one flexible annular plate located between and engaging with said seatings, means on the nut for keying engagement with a part non-rotatably associated with the cylinder when the damper is extended, whereby relative rotation between the kcylinder and the piston-rod rotates the nut on the piston-rod to adjust it axially and vary the loading of lthe valve member, and a bleed orifice through said nut and having an end extending towards said piston whereby movement of said nut towards and away from said piston moves said orice end with respect to said piston to eiect control of the rate of flow through said orifice.

References Cited in the tile of this patent UNITED sTATEs PATENTS Williams Sept. 20, 1938 

